Engineering and Microstructural Properties of Fiber-Reinforced Rice Husk-Ash Based Geopolymer Concrete

The concrete industry is a remarkable point source of carbon dioxide emission due to the disintegration of raw materials and burning of fuel during the cement manufacturing process. One efficient way to minimize such detrimental environmental effects is utilizing waste and byproduct materials as cement replacements in concrete. An alternative to the production of environmentally friendly concrete is the development of geopolymers. In this study, the possibility of creating structural rice husk ash (RHA)-based geopolymer concrete using high amounts of agricultural solid waste as a byproduct material is investigated. All the samples were reinforced by polypropylene (PP) fiber. The test results indicated that replacement by RHA-based geopolymer improved the mechanical properties of concrete and 100% replacement by geopolymer can be taken into consideration, having the best results environmentally, structurally, and economically. Moreover, the addition of PP fibers increased the flexural and splitting tensile strength. In addition, substantial CO2 reduction, as high as 63%, was measured to be emitted in the creation of the studied sustainable RHA-based geopolymer composites. From the microstructural point of view, reduction of the interfacial transition zone (ITZ) width between the paste and the aggregate is another outcome that could efficiently decrease water permeability. (C) 2018 American Society of Civil Engineers.